Railway traffic controlling



Patented Jan. 4, 1938 llNl'i'ED STATES RAILWAY TRAFFIC CONTROLLING APPARATUS Henry S. Young, Wilkinsburg,

The Union Switch & Signal Company,

Pa., assignor to Swissvale, Pa., a corporation of Pennsylvania Application August 14,

10 Claims.

My invention relates to railway traflic controlling apparatus, and particularly to apparatus for governing trafiicat points where two or more tracks intersect or converge.

I will describe one form of railway traflic controlling apparatus embodying my invention, and will then point out the novel features thereof in claims. 7

The accompanying drawing is a diagrammatic view illustrating one form of apparatus embodying my invention.

Referring to the drawing, the reference characters X and Y designate two intersecting railway tracks. Track X is divided, by means of insulated joints 2, into sections 4T and T. Track Y is divided, by means of insulated joints 2, into sections ST and IT. The sections 4T and ET I shall term approach sections and the sections 5T and 1T, containing the intersection W, I shall term detector sections.

Each section in each of the tracks X and Y is provided with a track circuit including a track battery 3 connected across the rails at one end of the section. Each section is also provided with a track relay connected across the rails at the other end of the section and designated by the reference character R with a prefix the same as the reference character of the associated section.

The detector sections ET and IT are made electrically separate from each other but each is continuous throughout its length. This is accomplished by means of insulated joints 2 adjacent the intersection W and conductors around the joints in the usual manner.

Trafiic from left to right over track X, I will term eastbound trafiic, While traffic from left to right over track Y, I will term southbound traffic.

Eastbound traffic on track X is governed by a traffic governing device here shown as a signal and designated by the reference character 4. Southbound traffic on track Y is governed by a traflic governing device here shown as a signal 7 and designated by the reference character 6.

Signals 4 and 6 are here shown as semaphore signals each having a blade occupying a normal position, as shown in the drawing, to indicate stop but movable to a diiferent position to indicate proceed. Associated with signals 4 and 6 are contacts 9 and i0 governed in accordance with the indication of the signals, respectively, by any usual and well known means. That is, each of contacts 9 and i0 is closed only when the associated signal indicates stop.

Each signal is provided with a normally ener- 1935, Serial No. 36,107

gized approach locking relay designated by the reference character MR with a prefix the same as the reference character of the associated signal.

Each approach locking relay is provided with a timing device here shown as a thermal relay and designated by the reference character TE with a distinguishing prefix.

The thermal relays 4TE and GTE are provided with contacts 13 and M, respectively, which contacts are closed when the associated thermal relay is in its initial or deenergized condition, and are provided with contacts 15 and i6, respectively, which contacts are closed only when the associated thermal relay completes its operation a predetermined interval of time after the heating elements I! and I8, respectively, are energized.

The reference characters 4K and 6K designate the usual manually operable releases which are provided for the emergency release of 'the approach locking associated with signals'4 and 6, respectively. Emergency release 4K is provided with contacts and H which are closed only when the release 4K is in its initial and operated condition, respectively; and release 6K is provided with contacts 4! and I2 which are closed only when the release 6K is in its initial and operated conditions, respectively.

It will be noted that the relay contacts are not in all instances directly under the relay actu ating such contacts. Each such contact, however, is provided with the same reference character as that applied to the actuating relay.

The signal 4 is provided with a circuit which passes from terminal B of a suitable source of current through back contact 20 of track relay 4TB, contact l4 of thermal relay GTE, front contact 2| of approach locking relay 6MB, front contact 22 of track relay 5TB, front contact 23 of track relay ITR, contact 4! of emergency release 6K, and signal 4 toterminal C of the same source of current. Thus, signal 4 may be automatically caused to indicate proceed when relay 4TR is released by a train occupying section 4T, provided that the approach locking relay BMR, is in its normal condition, that detector sections 5T and IT are both unoccupied and that thermal relay GTE and emergency release 6K are both in their initial conditions.

The signal 6 is provided'with a circuit which passes from terminal B through back contact 24 of track relay 6TB, contact l3 of thermal relay 4TE, front contact 25 of relay 4MB, front contact 26 of relay ITR, front contact 21 of relay 5TB, contact 40 of emergency release 4K, and signal 6 to terminal C. Thus, signal 6 may be automatically caused to indicate proceed when relay ETR. is released by a train occupying section 6T provided that the approach locking relay iMR is in its normal condition, that detector sections ST and 'lT are both unoccupied and that thermal relay 4TE and emergency release 4K are both in their initial conditions.

The approach locking relay 4MB is provided with three pickup circuits and with one stick circuit. The first pickup circuit for relay 4MB passes fromterminal B through contact 9 closed when signal 4 indicates stop, contact H of emergency release 4K and relay 4MR to terminal C. The second pickup circuit passes from terminal B through contact 9, front contact 28 of relay 4TB, back contact 29 of relay 5TB, and relay 4MB, to terminal C. The third pickup circuit passes from terminal B through contact 9, contact l5 of thermal relay 4TE and relay 4MR to terminal 0. The stick circuit passes from terminal B through contact 9, front contact 30 of relay 4MB and relay 4MB, to terminal C. Thus relay iMR will be released when signal 4 is caused to indicate proceed, and may be energized again when signal 4 indicates stop either by the operation of the emergency release 4K, or by the release of relay 5TB. provided relay 6TB. is energized, or by relay 4TE completing its operation. When relay 4MB. is energized it will be stuck in that condition as long as signal 4 indicates stop.

The approach locking relay BMR is also pro vided with three pickup circuits and a stick circuit. The first pickup circuit passes from terminal B through contact l0 closed only when signal 6 indicates stop, contact [2 of emergency release 6K and relay 6MB to terminal C. The second pickup circuit passes from terminal B through contact l0, front contact 3| of relay 6TB, back contact 32 of relay 'ITR, and relay BMR. to terminal C. The third pickup circuit passes from terminal *3 through contact l0, contact N5 of relay GTE, and relay 6MB to terminal 0. The stick circuit passes from terminal B through contact I 0, front contact 33 of relay 6MB and relay 6MB to terminal 0. Thus relay 6MB will be released when signal 6 is caused to indicate proceed and may be energized again provided signal 6 indicates stop, either by the operation of emergency release 6K, or by the release of relay 'ITR provided rela y BTR is energized, or by relay GTE completing its operation. When relay 6MB is picked up it will be held in that condition as long as signal 6 indicates stop.

The thermal relay 4TE is provided with the circuit which passes from terminal B through back contact 34 of relay 4MB, front contact 35 of relay 4TR and heating element I! to terminal C. The thermal relay STE is provided with a similar circuit which passes from terminal B through back contact 36 of relay BMR, front contact 37 of relay 8TB, and heating element I8 to terminal C. Thus, the operation of either relay 4TE or relay GTE may be initiated when the associated approach locking relay is released provided the track relay for the corresponding approach section is in its energized condition.

Having thus described in general the various parts of the apparatus embodying my invention, I will now explain their operation.

'I shall first assume that with all parts in their normal condition as shown in the drawing, an

eastbound train enters section 4T so that relay 4TB, becomes released. When relay 4'IR is released, signal 4 will be automatically caused to indicate proceed by the closing of back contact 20 of relay 4TB in the previously traced control circuit for signal 4. When signal 4 indicates proceed, contact 9 will be opened so that approach locking relay 4MB becomes released. When relay 4MB, is released it will be noted the control circuit for signal 6 will be opened by the opening of front contact 25 of relay 4MB so that signal .6 can not be caused to indicate proceed.

When the train enters section 5T, the control circuit for signal 4 will be interrupted by the opening of front contact 22 of relay 4TB so that signal 4 will be caused to assume its stop position. When the rear of the train leaves section 4T so that relay 4TB again assumes its energized con dition, it will be noted that the second of the previously traced pickup circuits for relay 4MB will be'closed so that relay 4MB. will again assume its energized condition. When the train departs from section 5T so that relay 5TB. again assumes its energized condition, all parts will be in their normal condition ready for the next train.

I shall next assume that an eastbound train on track X, after entering section 4T and releasing relay reverses its direction and departs from section 6T without entering section 5T. Mien this occurs, signal 4 will again assume its stop condition and relay 4MR, will remain in its released condition until such time as one of its pickup circuits is closed. When relay 4MR is in its released condition and relay 4TB. is in its energized condition, it will be apparent that the previously traced control circuit for thermal relay 4TB will be closed. The closing of this control circuit will initiate the operation of the relay dTE. Shortly after the operation of relay 4TE-is initiated, contact l3 of relay 4TE in the control circuit for signal 6 will become opened. When relay QTE completes its operation at the expiration of a given time interval so that contact l5 becomes closed, the third of the previously traced pickup circuits for relay 4MB, will be closed. Thus, relay 4MB will again assume its energized condition, to close its front contact 25 in the control circuit for signal 6 and to disconnect energy from heating element I! of thermal relay 4TE, so that contact l3 of relay 4TE in the control circuit for signal 6 may again become closed upon the cooling of heating element IT.

From the foregoing description of the apparatus embodying my invention, it will be obvious that whenrelay 4MB is released by the clearing of signal 4 in response to the occupancy of section. 4T by a train, the relay 4MB can not be immediately restored to its energized condition if such train departs from section 4T without entering section 5T. That is, under this condition relay 4MR will remain released until relay i-TE completes its operation a measured interval of time after the train leaves section 4T. As long as relay 4MB, is in its released condition, signal 5 can not be cleared. Therefore, momentary losses of shunt by a train occupying section 4T will not permit the clearing of signal 6 for another train in section 5T desiring to move over the intersection W. If a momentary loss of shunt should occur While a train moving towards the intersection is occupying section 4T, the relay 4MB can not be energized until a measured amount of time is consumed which amount.

will be sufiicient to allow the train in section 41 either to come to a stop before passing signal t or to enter detector section 5T. In either event,

the'two trains will lee-prohibited from moving over the intersection simultaneously.

scribed for signal 4 and its associated apparatus;

It will be understood that usually directional stick relays will be provided for each track X and Y which relays will prevent the clearing of the signals when trains receding from the intersection occupy the approach sections GT and ET. It will be understood also that. usually tracks X and Y will be provided with signals to govern trafic movements over the intersection in the directions opposite to those governed by signals 4 and'ii. Since such directional stick relays and opposing signals are not required for the purposes of explaining my invention, they are omit ted for the sake of simplicity.

Although I have herein shown and described only one form of apparatus embodying my invention; it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track having an approach section, a traffic controlling device for said stretch having a normal condition but operable to a different condition, means for at times automatically causing said traffic controlling device to assume such diiierent condition when a trainenters said approach section, a normally energized approach locking relay, means for deenergizing said approach looking relay when said traffic controlling device is in such diiierent condition, a timing device, means for initiating the operation of said timing device when the train leaves said approach section effective if said approach locking relay is then deenergized, means for energizing said approach locking relay when said timing device completes its operation, and another traffic controlling device rendered inoperative as long as said approach locking relay is deenergized.

2. In combination, a stretch of railway track having an approach section including a track circuit having a track relay, a traffic controlling device for said stretch having a normal condition but operable to a different condition, means for at times automatically causing said traffic controlling device to assume such different condition when the track relay is released by a train entering said approach section, a normally energized approach locking relay, means for deenergizing said approach locking relay when said traffic controlling device is in such different condition, a timing device, means effective to initiate the operation of said timing device when the track relay is energized by the train leaving the approach section provided said approach locking relay is then deenergized, means effective to energize said approach locking relay when said timing device completes its operation, and another traffic controlling device rendered inoperative as long as said approach locking relay is deenergized.

3. In combination, a stretch of railway track, a signal for said stretch, means for at times automatically causing said signal to indicate proceed when a particular approach zone is occupied by a train, an approach locking relay deenergized when said signal indicates proceed,

a timing device, means for initiating the operation of said device when the train leaves said approach zone provided said approach locking relay is then deenergized, 'means for energizing said approach locking relay when said timing device completes its operation, and another signal for an intersecting track controlled by said approach locking relay.

41.. In combination, a stretch of railway track divided into an approach section and a detector section each having a track circuit including a track relay, a signal for said stretch, an approach locking relay, a thermal relay controlled by said approachlocking relay and the track relay for the approach section, a circuit for said approach locking relay including a contact closed when said signal indicates stop and a back contact of the track relay for the detector section as well as a front contact of the track relay for the approach section, another circuit for said approach locking relay including a contact closed when the signalindicates stop and a contact of said thermal relay, and another signal controlled by said approach locking relay.

5. In combination, a stretch of railway track including an approach section having a track relay, a signal for said stretch-controlled by said track relay, an approachlocking relay controlled by said signal, a'thermal relay for at times controlling said approach locking relay, a circuit for said thermal relay including a front contact of the trackrelay for the approach section and a back contact of the approach locking relay, and

a traiiic controlling device controlled by said approach locking relay.

6. In combination, two intersecting railway tracks each having an approach section and a detector section, said detector sections including the intersection; two signals,one for each track for governing trafiic over the intersection, means for at times causing one of said signals to indicate proceed when the associated approach section is occupied by a train provided the other signal is indicating stop and provided both detector sections are unoccupied, two normally energized approach locking relays one for each signal, means for causing the approach locking relay associated with each signal to become deenergized when that signal is caused to indicate proceed, means for disabling the control of one signal when the approach locking relay associated with the other signal is deenergized, and means for energizing each approach locking relay when the associated signal indicates stop efiective when a train enters the detector section and leaves the approach section of the stretch associated with that signal.

7. In combination, two intersecting railway tracks each including an approach section and a detector section each such section having a track circuit including a track relay, two signals, one for each track for governing trafllc over the intersection, means for at times causing one of said signals to indicate proceed when the track relay for the associated approach section is deenergized by a train provided the other signal is indicating stop and provided the track relays for both detector sections are energized, two normally energized stick relays one for each track and each such stick relay effective when deenergized to prevent the clearing of the signal for the other track, a pickup circuit for each stick relay including a front contact of the track relay and a back contact of the track relay for the approach and detector sections respectively of the track associated with such stick relay, and'a stick circuit for each stick relay including a contact closed only when the signal for the associated track indi cates stop. 7 v

8. In combination, a stretch of railway track divided into an approach section and a detector section each having a track circuit including a track relay, a signal for said stretch at times automatically controlled by the track relay for the approach section, a normally energized approach locking relay, means for deenergizing said approach locking relay when said signal indicates proceed, a circuit for energizing said approach locking relay including a front contact of the track relay for the approach section and a back contact of the track relay for the detector section, and a traific controlling device'for an intersecting track controlled by another circuit including a front contact of the track relay for the detector section and a front contact of said approach locking relay whereby said other circuit for the control of said traific controlling device will not become effective during a momentary loss of shunt by a train occupying said approach section.

9. In combination, a stretch of railway track including an approach section and a detector section, a signal at the junction of said sections, means for at times causing said signal to indicate proceed efifective only if said approach section is then occupied by a train, locking means having an initial condition and a locking condition, means for causing said locking means to assume its locking condition when said signal is caused to indicate proceed, means effective to cause said locking means to assume its initial condition when said signal is caused to indicate stop by the train in the detector section provided the approach section is then unoccupied, other means for also causing said locking means to assume its initial condition when said signal is caused to indicate stop when the train vacates the approach section without entering the detector section, said other means being effective only upon the expiration of a given time interval after the train vacated the approach section, and traffic controlling means governed by said locking means.

10. In combination, a stretch of railway track including an approach section and a detector section each provided with a track circuit including a track relay, a signal at the junction of said sections, means for at times causing said signal to indicate proceed efiective only if the track relay for the approach section is then released, locking means having an initial condition and a locking condition, means for causing said locking means to assume its locking condition when said signal is caused to indicate proceed, means effective to restore said locking means to its initial condition when said signal is caused to indicate stop by the releasing of the track relay for the detector section provided the track relay for the approach section is then picked up, other means for also restoring said locking means to its initial condition when said signal is caused to indicate stop by the picking up of the track relay for the approach section, said other means being effective only upon the expiration of a given time interval after the track relay for the approach section becomes picked up, and traflic controlling means governed by said locking means.

HENRY S. YOUNG. 

